The covid-19 pandemic, which has ravaged the globe for three years, is still worrying specialists in the country, at a time when the epidemiological situation is under control. Government data confirm that, since yesterday (6), there are almost 10,000 new cases and 79 deaths in Brazil. In the world , on the 5th, 100 thousand and 800 new cases and 560 deaths were recorded.

This concern stems from the fact that variants and subvariants – such as XBB.1.5, the omicron subvariant that caused the recent spike in cases – are still in circulation and appearing every day. The low level of vaccination in some age groups, notably among the youngest, is also a warning factor.

The first case of covid-19 in Brazil was confirmed on February 26, 2020, in São Paulo. Since then, the country has gone through dark times, with schools closing, changes from face-to-face work to online work and many deaths. Now the situation is under control. “I think we are at the point of transition to the endemic phase, but we are still in a pandemic situation”, predicts Professor Eliseu Waldman, from the Department of Epidemiology at the Faculty of Public Health at USP. Therefore, the situation still deserves care.

Are we protected?
Waldman brings to light a determining point of the pandemic so far: the great seasonal variation defined in any viral situation that, due to the high circulation, has caused the emergence of a large number of variants. “And these variants, when they have characteristics of high transmissibility, determine epidemics”, he explains.

Even though they are epidemics of lesser intensity, they cause concern. This is because, even if a smaller portion of the population develops serious cases and subsequently dies, the goal is to avoid all kinds of suffering, which justifies the concern and maintenance of the state of emergency by the WHO (World Health Organization) . The epidemiologist points out that this decrease is due to the fact that a large part of the population has immunity.

He also says that “now the data suggest that we are at a turning point, probably in the course of this year we will have a continuous decrease in cases of deaths. But it will depend a lot on the characteristics of the variants that arise”.

Vaccination
Vaccination with Pfizer’s bivalent vaccine, which protects against the original virus, the omicron variant and its subvariants, should begin to be applied on the 27th of this month, according to the new vaccination campaign by the Ministry of Health. The vaccine arrives at a time when more than 19 million people have not completed the vaccination schedule against covid-19.

“The vaccine remains the great weapon against covid”, says Waldman. According to him, the goal is 95% to 100% coverage for the reduction of severe cases and deaths. Currently, the Ministry’s concern is with basic coverage, which is low for young people. “Now, we need to encourage the population to adhere to the vaccine. Even though we managed to achieve rates above the world average, they are far from desirable”, he recalls.

epidemiological situation
The epidemiological situation is better, but the virus is still circulating. The trend, according to the professor, is an annual dose, something that the Ministry of Health already plans to do. The vaccination strategy for covid-19, however, is still uncertain and there are doubts about it.

The characteristic of respiratory transmission and the variants have determined the distribution of the disease throughout the year, different from what happens with influenza, for example. Generally, the vaccinated population at the peak has good levels of antibodies, but in the case of covid, there is no such certainty.

The vaccine strategy has not yet been determined, due to the behavior of the virus and the composition of the vaccine. “The great advantage of the bivalent is that it contains strains of the omega variant in its formulation, therefore, a vaccine with greater similarity to the virus that circulates the most today”, says Waldman. For this, it is necessary to wait for the behavior of the disease in the endemic phase. “Everything indicates that it will also predominate in winter”, concludes the professor.